National Hockey League commissioner Gary Bettman and NHL union boss Don Fehr said Thursday they plan to investigate the recent deaths of three NHL players known for fighting and physical toughness. Wade Belak, an "enforcer" who played on five NHL clubs before retiring last March, was found dead in Toronto on Wednesday. He was 35. Former New York Rangers toughman Derek Boogaard died in May at age 28 in what was ruled an accidental mix of alcohol and a painkiller, oxycodone. And Rick Rypien, 27, of the Winnipeg Jets was found dead last month at his Canadian home. "While the circumstances of each case are unique, these tragic events cannot be ignored," Bettman and Fehr said in a joint statement. "We are committed to examining, in detail, the factors that may have contributed to these events, and to determining whether concrete steps can be taken to enhance player welfare and minimize the likelihood of such events taking place. "Our organizations are committed to a thorough evaluation of our existing assistance programs and practices and will make immediate modifications and improvements to the extent they are deemed warranted." All three players were known for taking and inflicting hits, many times suffering blows to the head. "It is important to ensure that every reasonable step and precaution is taken to make NHL players aware of the vast resources available to them when they are in need of assistance," Bettman and Fehr said. "NHL clubs and our fans should know that every avenue will be explored and every option pursued in the furtherance of this objective." The deaths come as concern grows around concussions and blows to the head in the NHL, especially as Pittsburgh Penguins star Sidney Crosby has not yet confirmed he will be back on the ice for pre-season workouts this month from concussions suffered in January. Crosby, who scored the gold medal goal in over-time for Canada's hockey team at the 2010 Vancouver Olympics, took two solid hits in January and missed the remainder of the NHL season.